This Application is a 371 of PCT/JP00/08239 filed Nov. 22, 2000.
The present invention relates to a preparation for nasal administration comprising a prostaglandin derivative as an effective ingredient.
Since prostaglandin (hereinafter referred to as xe2x80x9cPGxe2x80x9d) exhibits various important pharmacological and physiological actions in a trace amount, the syntheses of a great number of derivatives from natural PGs and the biological activities have been investigated with the intention of a practical use as medicines. Particularly, many compounds which have a triple bond between the 13- and 14-positions were synthesized by Sato et al, and among of these compounds are PG derivatives described in Japanese Patent Kokai Hei 7-233144.
The PG derivatives in the above-mentioned gazette are described to have an excellent lowering action of ocular tension and be able to be used as eye drops or an eye ointment. However, there have not been known a preparation for nasal administration comprising said prostaglandin derivatives or its sleep-inducing effect.
As a result of the extensive studies to solve the above purpose, the present inventors have found that the following prostaglandin derivatives, when combined with a certain polymer, have an excellent sleep-inducing effect by nasal administration, and thereby the present invention has been accomplished.
That is, an aspect of the present invention is to provide a preparation for nasal administration (hereinafter referred to as xe2x80x9cpreparation of the present inventionxe2x80x9d or xe2x80x9cpreparation of the present applicationsxe2x80x9d) which comprises as an effective ingredient a prostaglandin derivative represented by Formula (I): 
wherein X is a halogen atom, R1 is a C3-10 cycloalkyl group, a C3-10 cycloalkyl group substituted with C1-4 alkyl group(s) or a C4-13 cycloalkylalkyl group, R2 is a hydrogen atom, a C1-10 alkyl group or a C3-10 cycloalkyl group, m is an integer of 0 to 3,n is an integer of 1 to 4, and a wavy line is a bond which may be in the R or S-configuration, or a pharmaceutically acceptable salt thereof and a water-soluble polymer.
A further aspect of the present invention is to provide a preparation for nasal administration which comprises as an effective ingredient a prostaglandin derivative represented by Formula (A): 
or a pharmaceutically acceptable salt thereof and a water-soluble polymer.
A still further aspect of the present invention is to provide the above-mentioned preparation for nasal administration wherein the water-soluble polymer is at least one member selected from the group consisting of a bridged vinyl polymer and a water-soluble cellulose ether.
A still further aspect of the present invention is to provide the above-mentioned preparation for nasal administration wherein the water-soluble polymer is at least one member selected from the group consisting of hydroxypropyl cellulose, hydroxypropylmethyl cellulose, polyvinylpyrrolidone and methyl cellulose.
A still further aspect of the present invention is to provide the above-mentioned preparation for nasal administration wherein the water-soluble polymer is hydroxypropyl cellulose.
A still further aspect of the present invention is to provide the above-mentioned preparation for nasal administration wherein the water-soluble polymer carries the prostaglandin derivative represented by Formula (I) or (A) or the pharmaceutically acceptable salt thereof.
A still further aspect of the present invention is to provide the above-mentioned preparation for nasal administration wherein the prostaglandin derivative represented by Formula (I) or (A) or the pharmaceutically acceptable salt thereof adheres to the water-soluble polymer and/or disperses in the water-soluble polymer.
A still further aspect of the present invention is to provide the above-mentioned preparation for nasal administration wherein a coating layer comprising the prostaglandin derivative represented by Formula (I) or (A) or the pharmaceutically acceptable salt thereof as an effective ingredient dispersed in the water-soluble polymer adheres to the surface of the water-soluble polymer for carrying the effective ingredient.
A still further aspect of the present invention is to provide the above-mentioned preparation for nasal administration which is a sleep-inducing preparation.
A still further aspect of the present invention is to provide a kit of a preparation for nasal administration which comprises the above-mentioned sleep-inducing preparation and a device for administration thereof.
A still further aspect of the present invention is to provide a method for sleep-inducing which comprises administering nasally a pharmaceutically effective amount of the above-mentioned sleep-inducing preparation to a human.
The compounds of Formula (I) to be used in the present invention are illustrated in more detail as follows.
The compound of Formula (I) can be prepared according to the following reaction formulae. 
In the reaction formulae, R3 is a C1-10 alkyl group or a C3-10 cycloalkyl group, TBS is a tert-butyldimethylsilyl group, and X, R1, m and n are as defined above).
The above-mentioned reaction formulae are illustrated as follows.
(1) At first, a known compound of Formula (II) is reacted with 0.8 to 2.0 equivalents of an organic aluminum compound represented by Formula (III) in an inert solvent (e.g. benzene, toluene, tetrahydrofuran, diethyl ether, methylene chloride or n-hexane) at xe2x88x9210 to 30xc2x0 C., preferably 0 to 10xc2x0 C., according to the method of Sato et al. (Journal of Organic Chemistry, vol. 53, page 5590 (1988)) to stereospecifically give a compound of Formula (IV).
(2) The compound of Formula (IV) is reacted with 0.5 to 4 equivalents of a compound represented by Formula (V) or (VI) and 0.05 to 2 equivalents of a radical generator (e.g. azobisisobutyronitrile, azobiscyclohexane carbonitrile, benzoyl peroxide or triethylborane) and, if desired, using 1 to 5 equivalents of a radical reductant (e.g. tributyltin hydride, triphenyltin hydride, dibutyltin hydride or diphenyltin hydride) in an inert solvent (e.g. benzene, toluene, xylene, n-hexane, n-pentane or acetone) at xe2x88x9278 to 100xc2x0 C., thereby a compound of Formula (VII) is obtained.
Alternatively, the compound of Formula (IV) is reacted with 0.5 to 4 equivalents of a compound represented by Formula (V) or (VI) using 0.05 to 2 equivalents of a base such as organic amines (e.g. triethylamine, diisopropylamine, pyridine or dimethylaniline) or basic resins (e.g. polyvinylpolypyrrolidone, diisopropylaminomethyl-polystylene or (piperidinomethyl)polystylene) in an inert solvent (e.g. benzene, toluene, xylene, n-hexane, n-pentane or acetone) at xe2x88x9278 to 100xc2x0 C., thereby a compound of Formula (VII) can be obtained.
(3) The compound of Formula (VII) is reduced with 0.5 to 5 equivalents of a reductant (e.g. potassium borohydride, sodium borohydride, lithium tricyanoborohydride, lithium tri-sec-butyl borohydride or aluminum diisobutyl hydride-BHT (2,6-di-tert-butyl-p-cresol) in an organic solvent (e.g. tetrahydrofuran, diethyl ether, ethyl alcohol, methyl alcohol or toluene) at xe2x88x9278 to 40xc2x0 C. to give compounds of Formulae (VIII) and (VIIIxe2x80x2). These compounds of Formulae (VIII) and (VIIIxe2x80x2) can be purified by a conventional separation method such as a column chromatography.
(4) The compound of Formula (VIII) or (VIIIxe2x80x2) is mesylated or tosylated, for example, with 1 to 6 equivalents of methanesulfonyl chloride or p-toluenesulfonyl chloride in the presence of a base (e.g. triethylamine, pyridine or 4-dimethylaminopyridine) in a suitable solvent (e.g. pyridine or toluene) at xe2x88x9220 to 40xc2x0 C., followed by chlorination with 1 to 16 equivalents of tetra-n-butylammonium chloride to give a compound of Formula (IX) or (IXxe2x80x2) wherein X is a chlorine atom. Herein, bromination or fluorination can be also carried out in an ordinary manner. For example, bromination can be carried out by a reaction with 1 to 10 equivalents of carbon tetrabromide in the presence of 1 to 10 equivalents of triphenylphosphine and 1 to 10 equivalents of pyridine in acetonitrile, and fluorination can be carried out by a reaction with 5 to 20 equivalents of diethylaminosulfur trifluoride (DAST) in methylene chloride.
(5) The protective group of the hydroxyl group of the compound of Formula (IX) or (IXxe2x80x2), i.e. a tert-butyldimethylsilyl group is removed by using hydrofluoric acid, pyridinium poly(hydrogenfluoride) or hydrochloric acid under conventional conditions in a solvent (e.g. methanol, ethanol, acetonitrile, a mixture thereof or a mixture of these solvents and water) to give a PG derivative of Formula (Ia) or (Iaxe2x80x2) relating to the present invention, i.e. a compound of Formula (I) wherein R2 is a C1-10 alkyl group or a C3-10 cycloalkyl group.
(6) The compound of Formula (Ia) or (Iaxe2x80x2) is hydrolyzed using 1 to 6 equivalents of a base in a conventional solvent for hydrolysis to give a PG derivative of Formula (Ib) or (Ibxe2x80x2) relating to the present invention, i.e. a compound of Formula (I) wherein R2 is a hydrogen atom. Examples of the base to be used herein are lithium hydroxide and potassium carbonate, and examples of the solvent are acetonitrile, acetone, methanol, ethanol, water and a mixture thereof.
Furthermore, the compound of Formula (Ia) is hydrolyzed by a reaction with an enzyme in a buffer solution such as phosphate buffer or tris-hydrochloride buffer, if necessary, by using an organic solvent (e.g. a water-miscible solvent such as acetone, methanol or ethanol) to give the PG derivative of the present invention, i.e. the compound of Formula (Ib). Examples of the enzyme to be used herein are enzymes produced by microorganisms (e.g. enzymes produced by microorganisms belonging to Candida sp. or Pseudomonas sp.) and enzymes prepared from animal organs (e.g. enzymes prepared from pig liver or pig pancreas). Commercially available enzymes are, for example, lipase VII (derived from microorganism of Candida sp.; Sigma Co.), lipase AY (derived from microorganism of Candida sp.; Amano Pharmaceutical Co.), lipase PS (derived from microorganism of Pseudomonas sp.; Amano Pharmaceutical Co.), lipase MF (derived from microorganism of Pseudomonas sp.; Amano Pharmaceutical Co.), PLE (prepared from pig liver; Sigma Co.), lipase II (prepared from pig pancreas; Sigma Co.) or lipoprotein lipase (prepared from pig pancreas; Tokyo Kasei Kogyo Co.).
The amount of the enzyme to be used, while depending on the potency of the enzyme and the amount of the substrate (the compound of Formula (Ia)), is usually 0.1 to 20 parts by weight based on the substrate, and the reaction temperature is from 25 to 50xc2x0 C., preferably 30 to 40xc2x0 C.
The definitions of the substituents in the compounds of Formula (I) of the present invention are illustrated in more detail as follows.
The xe2x80x9chalogen atomxe2x80x9d as defined for X refers to a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and X is preferably a chlorine atom or a bromine atom, and especially preferably a chlorine atom.
The definitions for R1 are illustrated as follows.
Examples of the xe2x80x9cC3-10 cycloalkyl groupxe2x80x9d, either by itself or as a part of the xe2x80x9cC3-10 cycloalkyl group substituted with C1-4 alkyl group(s)xe2x80x9d are a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and a cycloheptyl group.
The xe2x80x9cC1-4 alkyl groupxe2x80x9d as a part of the xe2x80x9cC3-10 cycloalkyl group substituted with C1-4 alkyl group(s)xe2x80x9d refers to a straight or branched alkyl group, and examples thereof are a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group and a tert-butyl group.
Examples of the xe2x80x9cC3-10 cycloalkyl group substituted with C1-4 alkyl group(s)xe2x80x9d are a methylcyclopropyl group, a methylcyclohexyl group and an ethylcyclohexyl group.
Examples of the xe2x80x9cC4-13 cycloalkylalkyl groupxe2x80x9d are a cyclopropylmethyl group, a cyclobutylmethyl group, a cyclopentylmethyl group, a cyclopentylethyl group, a cyclohexylmethyl group, a cyclohexylethyl group and a cycloheptylmethyl group.
R1 is preferably a C5-7 cycloalkyl group, and especially preferably a cyclohexyl group.
The xe2x80x9cC1-10 alkyl groupxe2x80x9d as defined for R2 refers to a straight or branched alkyl group, and examples thereof are a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a 2-ethylpropyl group, a hexyl group, an isohexyl group, a 1-ethylbutyl group, a heptyl group, an isoheptyl group, an octyl group, a nonyl group and a decyl group.
Preferably, R2 is a hydrogen atom or a methyl group.
With regard to a preferable combination of m and n, m is 3 when n is 1, or m is 0 when n is 4.
Examples of the xe2x80x9cpharmaceutically acceptable saltxe2x80x9d are salts with an alkali metal (e.g. sodium or potassium), an alkali earth metal (e.g. calcium or magnesium), ammonia, methylamine, dimethylamine, cyclopentylamine, benzylamine, piperidine, monoethanolamine, diethanolamine, monomethylmonoethanolamine, tromethamine, lysine, a tetraalkyl ammonium and tris(hydroxymethyl)aminomethane.
The xe2x80x9cwater-soluble polymerxe2x80x9d as used in the present invention refers to a polymer which is soluble in water, and examples thereof are at least one member selected from the group consisting of a bridged vinyl polymer and a water-soluble cellulose ether.
The xe2x80x9cbridged vinyl polymerxe2x80x9d includes a bridged polyvinyl alcohol (e.g. polyvinyl alcohol), a bridged polyacrylic acid or salts thereof (e.g. polyacrylamide) or polyvinylpyrrolidone.
The xe2x80x9cwater-soluble cellulose etherxe2x80x9d includes hydroxypropyl cellulose, a hydroxyalkylmethyl cellulose (e.g. hydroxypropylmethyl cellulose), methyl cellulose, hydroxyethyl cellulose, ethylhydroxyethyl cellulose, carboxymethylhydroxyethyl cellulose, carboxymethyl cellulose sodium or cationic cellulose ether.
In view of the simple production and effectiveness of the preparation for nasal administration, preferable examples of the water-soluble polymer to be used are at least one member selected from the group consisting of hydroxypropyl cellulose, hydroxypropylmethyl cellulose, polyvinylpyrrolidone and methyl cellulose. Hydroxypropyl cellulose is especially preferably used.
The water-soluble polymer to be used herein includes various commercially available or synthesized ones of which solubility, substitution degree (i.e. viscosity) or particle size may be different, and they can be arbitrarily by chosen as long as having a purity usable for a pharmaceutical preparation.
The xe2x80x9cwater-soluble polymer carries the prostaglandin derivative of Formula (I) or (A) or the pharmaceutically acceptable salt thereofxe2x80x9d refers to a state in which the prostaglandin or the pharmaceutically acceptable salt thereof (hereinafter optionally referred to as xe2x80x9cdrugxe2x80x9d) is carried by the water-soluble polymer so as to be absorbed at the site of the drug absorption. Here, the water-soluble polymer which carries the drug is referred to as xe2x80x9ccarrierxe2x80x9d.
In view of the drug transition to the brain, the particle size of the water-soluble polymer carrier is preferably about 20 to about 250 xcexcm, especially preferably about 75 to about 250 xcexcm.
In the present invention, the xe2x80x9cdispersion of the drug in the water-soluble polymerxe2x80x9d refers to a state wherein the drug exists in the form of monomolecule in the water-soluble polymer. Preferably, the greater part of the drug exists in a solid-dispersion state (the drug is amorphous).
The dispersion state of the drug can be produced by an ordinary method such as, for example, a fusion method, a solvent method, a fusion-solvent method or a mechanochemical method.
Referring to a particular solvent method, the dispersion state of the drug can be obtained by dissolving the drug and the water-soluble polymer in a solvent, and removing the solvent.
The xe2x80x9cadhesion of the drug to the water-soluble polymerxe2x80x9d includes not only the direct adhesion of the drug to the water-soluble polymer but also the indirect adhesion of the drug to the water-soluble polymer via a binder, etc.
It is preferable that the drug adheres to the surface of the water-soluble polymer (including the case wherein a part of the drug is embedded in the water-soluble polymer, and the other part of the drug is exposed to the outside from the surface of the water-soluble polymer).
The water-soluble polymer to be used for the adhesion of the drug is, in view of the adhesiveness, preferably, one of which viscosity is high (e.g. about 400 cps (400 mpa.s) or more, more preferably about 1000 cps (1000 mpa.s) or more in a 2% aqueous solution).
The viscosity to be used here is kinetic-viscosity, and can be determined by a viscometer such as a Cannon-Fenske viscometer, a Cannon-Fenske viscometer for opaque solution, a Ubbelohde viscometer or Ostwald viscometer. Especially, the determination by Ubbelohde viscometer is preferable in view of the high precision. The viscosity data described in the present specification were determined under the environment at 37xc2x0 C. using a Ubberohde viscometer manufactured by Shibata Science Machine Industry Co.
The xe2x80x9cindirect adhesion via a binder, etc.xe2x80x9d includes the adhesion of a coating layer comprising the dispersed drug to the surface of the water-soluble polymer carrier. For example, the water-soluble polymer can be used as the coating layer.
In the present preparation, the adhesion of a coating layer comprising the drug dispersed in the water-soluble polymer to the surface of the water-soluble polymer carrier is more preferable than the direct dispersion of the drug to the surface of the water-soluble polymer carrier.
That is, the drug, when dispersed in the water-soluble polymer, exists in the form of monomolecule in the water-soluble polymer, therefore it has a preferably fast solubility rate.
The water-soluble polymer which is used for the coating layer and adheres to the surface of the water-soluble polymer carrier includes the above-exemplified one, and may be the same as or different from the water-soluble polymer to be used as a carrier, but is preferably one which has a low viscosity in view of easier dispersion.
The adhesion of the drug to the water-soluble polymer can be carried out according to an ordinary adhesion method, preferably, for example, according to an adhesion method comprising admixing the drug with the water-soluble polymer (and, if desired, heating), or an adhesion method comprising spraying a solution of the drug in a solvent or a solution of the drug and the water-soluble polymer in a solvent to coat the water-soluble polymer carrier (and, if desired, drying). These methods can be also used in combination.
Herein, the heating is preferably carried out at about 70 to 85xc2x0 C.
The xe2x80x9csolvent to be used for dissolving the drugxe2x80x9d refers to a pharmaceutically acceptable solvent such as alcohols or diluents thereof.
Methods for spraying or coating can be carried out by an ordinary method, for example, a method using a pan-coating, a fluidized bed coating apparatus or an airflow drying pan-coating apparatus, or a method using a wet granular such as, for example, a fluidized bed granular (an agitating fluidized bed granular).
The particle size of the drug carried by the water-soluble polymer thus obtained as described above can be adjusted to not more than about 250 xcexcm, if desired, by sieving.
With regard to a weight ratio of the water-soluble polymer to be used for carrying the drug of the present invention to the drug, an amount of the drug is preferably from about 0.001 to about 0.10 part by weight, and especially from about 0.002 to about 0.04 part by weight, per 1 part by weight of the water-soluble polymer.
To the water-soluble polymer which carries the drug of the present invention can be optionally added conventional additives unless the effect of the present invention is degraded, thereby the preparation for nasal administration can be also obtained.
Examples of the conventional additives are perfumes (e.g. menthol), coloring agents, lubricant (e.g. talc, magnesium stearate or a hydrogenated oil) and preservatives (e.g. p-oxybenzoate esters).
In order to avoid the loss of the drug of the present invention before use (e.g. before administration to the nasal cavity), the water-soluble polymer which carries the drug of the present invention (if desired, with additives) is filled into a capsule (hard gelatin capsule) every dosage unit to give an embodiment of the present preparation for nasal administration.
The amount of the effective ingredient in the present preparation is preferably from about 0.05 to about 5% by weight, especially preferably 0.1 to 3% by weight based on the total weight of the preparation.
The present preparation generally can be administered by spraying quantitatively in a form of a solution or a powder (including the powder filled in the hard capsule described above) containing the drug into the nasal cavity by use of a suitable nasal dropper or sprayer (e.g. a device for administration of powder). As a specific example of the administration method, a capsule filled with the powder is placed on a dedicated nasal sprayer with a needle, and run through by the needle, thereby minute holes were made on the upper and lower sides of the capsule, and the powder can be sprayed out therein by taking in air with a rubber ball.
The dose is varied by the age, body weight or conditions of a patient, but it generally is from 1 ng to 1 mg/day per adult as an amount of the effective ingredient.
The present invention makes it possible to provide a preparation for nasal administration which has an excellent sleep-inducing action. Furthermore, the present invention makes it possible to provide a preparation for nasal administration which has not only an elevated bioavailability (hereinafter referred to as xe2x80x9cBAxe2x80x9d) but also a highly direct effect on the brain. Still furthermore, the present invention makes it possible to provide a preparation for nasal administration wherein the prostaglandin is remarkably stable upon storage as shown in the following Experiment 4.